The present invention relates to a mounting device for a structure such as a solar panel and to a method of installing a solar panel.
The problems of anthropogenic climate change are well known. Micro-power generation, for example using solar panels, is an increasingly popular way to provide a renewable source of energy for domestic and commercial use.
Solar panels incorporating photovoltaic cells or heat collectors (such as flat plate collectors used for heating water) are typically large planar structures manufactured from relatively rigid, relatively lightweight materials. In use these structures must be placed in relatively exposed locations, such as rooftops and are typically inclined using a frame to present the greatest possible surface area to the sun.
Solar panels for a private dwelling typically have a surface area of about 1.5-3 m2 in cross section and are relatively thin, usually a few centimetres thick. Installations for larger dwellings or commercial properties may be substantially larger in area but, in general are of a similar thickness. Particularly in the case of photovoltaic cells, the cost of such arrangements is considerable. The size and arrangement of solar panel structures makes them susceptible to damage by winds and it is necessary to secure the panels to prevent them from being damaged or blown away in high winds.
It has been proposed to secure such panels to roofing by drilling into roof joists and securing the frame of the panel to the roof joists using bolts or screws. It is generally necessary to anchor the solar panel to many joists in order to spread the load. As such, many bolts and hence many holes may be required. This presents a problem, particularly for a flat roof, in that each of the holes must be individually sealed to prevent water seeping through the holes in the roof and damaging the building. One approach using a frame like system is described in Japanese patent JP-A-2000-064523 which employs a light weight channel shaped frame for installation of solar cell panels. The frames include holding portions which have sideways openings to allow insertion of a solar panel in a lateral direction. Mounting frames, such as wall mounts for screens (like those produced by AVF Group Ltd. http://www.avf-eco.com) provide another example of this approach.
Another option is to position large concrete blocks on a roof and to bolt the panel, or a support frame carrying the panel, to the concrete blocks. This has the advantage that it is not necessary to drill into the roof. However hoisting large blocks of concrete onto a roof and manoeuvring them can present a substantial hazard and/or risk damaging the structure of the roof. In an attempt to reduce the mass of ballast required to mitigate this hazard, U.S. Pat. No. 6,570,084 describes a pressure equalising photovoltaic assembly and method in which a PV assembly includes a base, a PV module and a support assembly securing the PV module to a position overlying the upper surface of the base. Vents are formed through the base. A pressure equalisation path extends from the outer surface of the PV module, past the peripheral edge of the PV module to and through at least one of the vents, and to the lower surface of the base to help reduce wind uplift forces on the PV assembly. Another ballasted system is described in International Patent Application publication number WO2009/120923 which employs a solar module integration system including ballast, a sole mechanically linked to the bottom surface of the ballast and a link member embedded in the ballast, an attachment module mechanically coupled to the link member, and a deflector mechanically coupled to the link member. The frame is electrically earthed and cabling for a solar panel module is routed through a wire chase in the frame.
As set out in the foregoing paragraphs, the problem of secure solar panel mounting has been addressed using a number of different approaches yet there remains an unmet need in the art for a reliable, robust, easily transportable and easily installed mounting device for solar panels.
Aspects and examples of the invention are set out in the claims and address at least a part of the above described technical problem.